Apparatus for treating metals.



S. T. WBLLM AN.

APPARATUS FOR TREATING METALS.

APPLICATION FILED AUG. 18, 1911.

1,116,772. Patented N0v.10, 1911.

2 SHEETS-SHEET 1.

22427225555: fZZZ/FZZ/JI' Jinn-22557 I S. T. WELLMAN. APPARATUS FORTREATING METALS.

APPLICATION FILED AUG. 18, 1911.

Paten td Nov. 10, 1914.

2 SHEETSSHEET 2.

nrrED sT T s PATENT oFFIcE.

'sAmUEI; 'Lr. WELLHAN, or CLEVELAND, OHIO;

the city of Cleveland; State. of Ohio, have ini ented certain new anduseful Improvements in Apparatus for Treating Metals, of which thefollowing is 'a specification.

Tnthe production of pig iron by elec-' tricity, one form of furnace hashad the re ducing shaft over'the crucible or melting chamber, the shapeof the furnace being something like an'ordinary blast furnace exceptthat the crucible or melting chamber is flared out so that theelectrodes can be inserted through the roof on an incline into thecharge. The heat in the crucible is mostly produced byelectricity, bythe use of carbon or graphite electrodes. The heat is producedby thecurrent from the electrodes passing through the carbon in the charge,enough charcoal or coke being charged to furnish gas for the reductionof the iron ore and also to saturate the iron with the carbon after itis reduced and melted. v

The production of the necessary heat in the crucible by electricity, inthis form of furnace, is only accomplished with great difiiculty, beingunsteady owing to the fact that cold material is constantly coming intothe crucible from the shaft, this sometimes hangs up and comes down alarge quantity at once. The electrodes must enter the fun nace crucibleat an angle and on this account the pressure of the ore. which entersfrom the top through the middle of the crucible, frequently breaks oifthe electrodes causing great delay and expense. The electrodesbeing'embedded' in the ore and carbon the part that is inside thefurnace can: not be seen, and the manner in which the melting is goingon cannot be determined except the amount of electricity which is being,taken. The condition of the bath cannot be determined and .110 tests canbe taken to determine the quality of the metal bathfl" It is alsoditlicult to determinethe quantityof th e meltedmetal which the cruciblecontains.

It is one object of my. invention to io'r err come these ob ections atthe same Vt mere-L taming the many advantages of using elec-y tricity asa heating agent.

' My improvement contemplates separat- APPARATUS FOR TREATING METALS.

i Specification of Letters Patent. Patenfe'd N 10, 1914, Applicationfiled AugustiB, 1911. Serial No. 6%,8-31v ing the operations of reducingand melting. making two steps,,the first, or reducing of the ore beingaccomplished in a new and improved manner. I

The furnace charge, which is made up in the same manner as where thecombined reducing and melting furnace is used, being say three or fourparts of iron ore and one part of charcoal or coke, with the addition oflimestone or such other fluxes as may. be necessary, is charged into asmall furnace Thisconsists of a brick lined chamber. This chamber isopen at both top and bottom, being closed by a cover on top when inoperation. The bottom is also closed by a brick lined charging box. Thischarging box is supported in a cradle, suitable means being provided forraising and lowering the cradle. The reduction'is accomplished withelectricity, two electrodes passing down through the core! of thefurnace. these being connected with the proper electric wires or cables,the current passing through them and from one to the other through thecharge. The starting of the furnace may be aided by putting charcoal orcoke in the bottom of the box, which is then fired'andheating andreducing in this chamber can be carried to a point where the ore issimply reduced to a spongy iron or it can be reduced first to spongyiron and then to a metal bath containing: mo e or less carbon.

The fi'ont'orf'cha rging side of the melting furnace and reducers may beplaced on the same line. An ordinary. charging;- machine my runon railsin front of tlic furnace so that the chargingvbox can be carried irom lthe reducing to the melting. furnace, Or in case of themcltin v furnaceand reducing a V k. V b

furnaces facing each other. they might be servedb a; chargingmechinewhich wuuici be carried on'an ,(Werhead traveling crane,

the carrier of which' would be turned degrees in making the transfer.

Men the reduction has gone as far as the charcoal,the carbon of whichcombines with oxygen in the iron ore causing a large amount of gas. Thecharging box is then quickly transferred by the charging ma,

chine, in the usual manner, to the melting crucible or furnace. Being ata very high temperature this quickly melts. A number of thesereducingfurnac es would be provided for one melting furnace, ,The'crucible or melting furnaces used need not necessarily be electricallyheated, but a Siemens regenerative furnace heated by producer gas, oroil, or other similar devices may be used.

A flue may be provided at each end of each reducing furnace. Each set offlues of all the furnaces being connected together. When the reductionis going on, the waste gases which are rich in carbonic oxid gas passout through one flue to the main gas flue, the opposite flue beingclosed. When the charge is being heated preparatory to receiving theelectric current a blast pipe from a blower is pushed in through a flueand the gases from the reducers which are receiving the electric currentpass through the main flue into the box and are burned with the air thatenters through the blast pipe. The gases from the melting chamber mightbe so used. The damper having been opened the products of combustionpass out through the oppositeflue, which leads to the chimney. By thismeans the waste gases are utilized, first to bring the charcoal toincandescence so that it will take the electric current, and second toheat up the ore and the remainder of the charge, this resulting ineconomy of power and saving of time.

Extending across the charging box and between the electrodes is a raisedportion or bridge of the nonconducting lining for the purpose of cuttingor separating any iron thatmay melt and run down into the bottom [of thebox into two portions and thus pre- ,'."venting it from acting as a pathor conv ductor for the electric current, the effect of which would bethat the bulk of the current would pass throughthis melted or heatediron without causing any reduction of the ore. The metallic iron being abetter conductor the electric current would pass through it instead ofthrough carbon of the charge as desired.

It is dillicult, if not impossible, to bring every charge-in all thereducing furnaces into exactly the same condition, but this is notnecessary as they are added successively to the melted bath in the.melting furnace. This bath can be tested by taking small the metal inthe bath is not what is desired it may be changed by proper'treatment oraddition. If pig iron is the product desired the bath may be keptcovered most. of the time with a layer of carbon with the object ofsaturating the iron with .it and giving theiron a coarse open fracturewith large crystals, this also saves the electrodes from beingcorrodedby any unre'duced ore which may be present. On the other hand if steelis the product desired as little carbon as possible is taken to themelting chamber or furnace and if carried over. it naturally floats ontop of the bath and can be easily skimmed of? through the charging door.

In the old shaft furnace or combination of reducing furnace and meltingfurnace only pig iron or iron saturated with carbon can be made, as'noopportunity is had to test the bath before tapping or to change itscomposition by any manipulations. But

. with my improved plan of separating the reducing and melting, anopportunity is bad for testing and manipulating the charge in themelting chamber as is had in the ordinary open hearth steel process, andit is thus possible to make, as a finished product, the softest opengrained pig iron, or high or low carbon teel; as may be desired. Inmaking steel a smaller. amount of carbon may be charged into and used inthe reducing furnace than in making pig iron, only enough being used toreduce the ore, a minimum amount being carried over to the meltingfurnace.

In the accompanying drawings which show one concrete embodiment of myinvention, Figure lis a general view of a plant for producing pig ironand steel in accordance with my invention. Fig. 2 shows in adiagrammatic way,'the relative positions of the reducing chamber and ofthe melting chamber and crucible. Fig. 3 is a. longitudinal verticalsectiongof the reduc ing chamber. Fig. 4 is a transverse verticalsection on a line 44of Fig. 3.

The reducing chamber 1 consists of a removable cover '2 through whichthe charge is introduced, and under which is the stationary body portion3 which opens below into the removable bottom closure 4 which is of thewell known form generally called in the art a charging box and providedwith a nonconducting refractory lining. The electrodes 5 and 6 passthrough openings in the removable cover and extend through the bodyportion 3'and into the charging boxeon opposite sides of a transverseridge 7 of insulating material for preventing the flow of currentthrough molten metal which may gather at the bottom of the vessel. Thecharging box 4 is supported in a cradle 8 by which it may be raised or.lowered into and away from com tact with the-bodyportion "of" thereducing cause their combustion and" initiate a re- '10 ducing actionlhen this takes place the products of combustionare led out through aflue 12 provided ivith avalve 13 and opening into a tunnel leading to achimney 15.

pleted either by the. use of The'charg-ingibox 4 at the bottom of thereducing chamber-isof a capacity to contain the entire charge'whenreduced and is adapted to be engaged by the charging machine 16 by whichit may *be transported to and emptied into thefmelting chamber orcrucible 17 in which the treatment is comelectricity through theelectrodes-18hr by other well known means.

In Fig. 2 I have shown two banks of reducing chambers, the bank-A beingdisposed opposite the crucible 17 so that the charge ing machine musthave a revolving motion. The bank B onthe other: hand, being arranged inline With the crucible may be served by a charging machine which. hasmerely longitudinal, lateral and vertical movements.

While I have described the particular arrangement shown in the drawingsin some detail my invention isnot confined to this specificarrangemenh-but may be availed of in essence in other Ways.

I claim as my invention:

1. In metallurgical apparatus, a chamher for containing a charge of oreand flux, electrodes in the chamber for causing reduction of the ore, aremovable closure at the bottom to the reducing chamber for holding thereduced charge, a chamber for con tinuing the treatment, means forremoving the closure and charging its contents, while still hot, intothe last mentioned chamber, and electric means for completing thetreatment of the ore in the last named chamber.

2. In a reducing furnace, a top, a body portion, a base portion, aninsulating ridge extending acres the bottom of the base portion,electrodes extending through the body portion and on opposite sides ofthe ridge, and means for removing the base portion containing thereduced charge.

3. In metallurgical apparatus, a plurality of reducing chambers, eachhaving a removable top, a stationary body portion a iemovable baseportion adapted to contain the reduced material, and provided with arefractory insulating ridge extending across its bottom, and electrodesextending through the body portion on opposite sides of the ridge; amelting vessel, and a crane adapted to engage the respective removablebase portions'ofthe reducing chambers and intro-- duce their contentsinto the melting vessel.

4. In metallurgical apparatus, a plurality of reducing chambers, aremovable top for each, a stationary body portion for each, a

removable base portion for each adapted to contam the reduced material,an insulating ridge extending across the bottom of each reducingchamber, and electrodes extending through the body portion of each onopposite sides of the ridge; a meltihg vessel, a crane adaptedto engagethe removable base portions of the, reducing chambers and tointroducetheir contents into the melting vessel, and means forcompleting the treatment of the material in the melting vessel.

5. In a reducing furnace, a removable top, a stationary body portion, aremovable base portion adapted to contain the reduced material andprovided with an upwardly extending refractory insulating ridge, andelectrodes extending through the body portion and on opposite sides ofthe ridge.

6. In metallurgical apparatus, a rectangular closed chamber forcontaining a charge, electrodes in the chamber for causing reduction ofthe ore, a removable closure at the bottom of the reducing chamber forholding the reduced charge, a chamber for continuing the trcatment,means for remov ing the closure and charging its contents into thechamber for continuing the treatment, and. means for completing thetreatment of the ore in the last named chamber.

'2'. In a. reducing furnace, a removable top, a stationary body portion,a removable base portion adapted to contain the reduced material, anupwardly extending insulating ridge extending across the bottom of thebase portion, electrodes extending through the body portion and onopposite sides of the ridge, means for removing the base portioncontaining the reduced charge.

8. In a reducing furnace, a top, a. body portion, and a charging boxadapted to close the bottom of the furnace and to receive the reducedmaterial.

9. In an electric reducing furnace, a charging box forming the bottomand receiving the reduced material 10. In metallurgical apparatus, achamber for containing a char e, electrodes in the chamber for causingreduction of the ore, a removable closure at the bottom to the reducingchamber for holding the reduced charge, a chamber for continuing thetreatment, means for removing the closure and charging its contentsWhile still hot into the chamber for continuing the treatment with othercharges, means for completing the treatment of the ore in the last namedchamber.

11. In metallurgical apparatus, a plurality of electric reducingchambers, oppositely disposed gas fiues in each chamber, a valve in oneline and a blast pipe in the other flue, means for operating the valve,and means for introducing air under pressure through the blast pipe. 12.In metallurgical apparatus, a plurality of reducing chambers, in eachchamber a flue acting alternately as inlet and outlet for gases, a blastpipe for introducing air when the flue acts as inlet and therebyproducing combustion of the gases, another'flue' acting as outlet whenthe first mentioned flue acts as inlet, and a valve for closing thesecond flue when, the first flue acts as outlet.

' In metallurgical apparatus, a plurality of electric reducing chambers,oppositely disposed gas fiues in each chamber, a valve in one flue and ablast pipe in the other flue, means for operating the valve, means forintroducing air under pressure through the blast pipe, a tunnelconnecting the flues having valves with each other and with a chimney,and a tunnel connecting the flues having blast pipes with each other.

14. In metallurgical apparatus, a plurality of reducing chambers eachhaving electrodes and removable bottoms With insulating ridges betweenthe'electrodes, a vessel, means for introducing the contents of aplurality of reducing chambers into the vessel, and means for continuingthe treatment of the mixture.

15. In a reducing furnace, a body portion, and a removable base portionprovided with an upwardly extending ridge.

16. In a reducing furnace, a body portion, and aremovable base portionadapted to contain reduced material and provided with a refractoryinsulating ridge.

17. In a reducing furnace, electrodes, a body portion, a removable baseportion, and an insulating ridge in the base portion and between theelectrodes.

Signed at Cleveland, this 16th day of August, 1911.

SAMUEL \Vitnesses KARL FENNING, ELIZABETH M. SWEENEY.-

T. WELLMAN.

Copies of this patent may 'be' obtained for five cents each, byaddressing the Commissioner of yatents,

' Washington, I). G. i

